Transition State Analogue Structures of Human Phosphoglycerate Kinase Establish the Importance of Charge Balance in Catalysis

• DOI: 10.1021/ja100974t
• Publication Date: 2010-04-19T11:32:01Z
• Authors: Matthew J. Cliff; Matthew W. Bowler; Andrea Varga; James P. Marston; Judit Szabó; Andrea M. Hounslow; Nicola J. Baxter; G. Michael Blackburn; Mária Vas; Jonathan P. Waltho
• Keywords: Phosphoglycerate kinase; Transition state analog

Transition state analogue (TSA) complexes formed by phosphoglycerate kinase (PGK) have been used to test the hypothesis that balancing of charge within transition dominates enzyme-catalyzed phosphoryl transfer. High-resolution structures trifluoromagnesate (MgF3−) and tetrafluoroaluminate (AlF4−) PGK determined using X-ray crystallography 19F-based NMR methods, revealing nature catalytically relevant this archetypal metabolic kinase. Importantly, side chain K219, which coordinates α-phosphate group in previous ground structures, is sequestered into coordinating metal fluoride, thereby creating a environment complementary transferring group. In line with dominance balance organization, substitution K219A induces corresponding reduction bound aluminum fluoride species, changes trifluoroaluminate (AlF30) complex. The AlF30 moiety retains octahedral geometry observed AlF4− TSA complexes, endorses proposal some widely reported trigonal transfer enzymes may misassigned reality contain MgF3−.